The demand for increasing performance in communications technology is ever increasing. For example, the need has been growing in the industry to transmit increasingly larger quantities of data at increasingly faster speeds. This has given rise to the need for more efficient processing of received data in communication receivers. Embodiments of the present invention provide improvements to producing estimated metrics from digital samples of a received communications signal carrying quadrature modulated symbols in a communications receiver that supports multiple symbol modulation formats. In some embodiments, the improves include processing speed and/or efficiency.